Multimedia-capable computer management system for selectively operating a plurality of computers

ABSTRACT

The present invention provides an intelligent, modular multimedia computer management system for coupling a series of remote computers to one or more user workstations to allow each user workstation to selectively access and control one or more remote computers. The computer management system incorporates a centralized switching system that receives keyboard, cursor control device, audio, and auxiliary peripheral device signals from the user workstation and transmits and applies the signals to the remote computer in the same manner as if the keyboard, cursor control device, audio input source, or auxiliary peripheral device of the user workstation were directly coupled to the remote computer. Also, the user workstation receives audio signals and auxiliary peripheral device signals from the remote computer. In addition, the multimedia computer management system transmits video signals from the remote computer over an extended range for display on the video monitor of the user workstation.

FIELD OF THE INVENTION

The present invention relates generally to a computer management systemfor coupling a plurality of remote computers (e.g., personal computers,servers, etc.) to one or more user workstations to allow a system userto selectively access or control the plurality of remote computers usingthe user workstation's keyboard, video monitor, mouse, audio outputdevice, audio input device or input/output (“I/O”) module. Specifically,audio generated internal to or external to (but physically near) theremote computer may be heard at the user workstation and audio createdat the user workstation may be heard at the remote computer utilizingaudio input and output devices coupled to the computer management systemor the remote computer. Furthermore, I/O modules located at either theuser workstation or the remote computer allow auxiliary peripheraldevices (i.e., serial devices, parallel devices, Universal Serial Bus(“USB”) devices, switch contacts, auxiliary audio channels, etc.) to beaccessed and controlled bi-directionally by either the user workstationor the remote computer.

BACKGROUND OF THE INVENTION

In a typical multiple computer environment, a Local Area Network (“LAN”)or Wide Area Network (“WAN”) allows for each computer, or server, to beconnected to several other computers such that the resources of eachconnected computer, or server, are available to each of the connectedcomputers. In this networked environment, a dedicated keyboard, videomonitor, mouse, audio output device, audio input device, and/orauxiliary peripheral devices may be employed for each computer orserver.

To maintain proper operation of the LAN or WAN, the system administratormust maintain and monitor the individual computers including theservers. This maintenance frequently requires the system administratorto perform numerous tasks at the user console that is associated withand physically located at the computer or server. For example, to reboota computer or to add or delete files, the system administrator is oftenrequired to operate the computer or server using its local, attachedkeyboard, mouse, video monitor, audio devices, and/or auxiliaryperipheral devices, which may be located at a substantial distance fromthe system administrator's computer and from other computers or serversconnected to the LAN or WAN. Consequently, to accomplish the task ofsystem administration, the system administrator must often physicallyrelocate to the user consoles of remote computers and servers.

One alternative to physical relocation of the system administrator isthe installation of dedicated cables that connect each remote computeror server to the system administrator's computer in a manner that allowsthe system administrator to fully access and operate the remotecomputers or servers. However, such an alternative requires substantialwiring and wire harnessing, both of which may require tremendous costthat increases each time a new computer is added to the system.Additionally, as the distance between the system administrator'scomputer and the computer equipment increases, a decrease in the qualityof the transmitted signal often results. Thus, dedicated cables betweenthe system administrator's computer and remote computer equipment maynot provide a feasible alternative.

In addition to the ease of managing a networked computer environment,space is also an important concern for many networked computerenvironments, especially large-scale operations such as data-centers,server-farms, web-hosting facilities, and call-centers. These computerenvironments typically require space to house a keyboard, video monitor,mouse, audio output device, audio input device and/or auxiliaryperipheral devices for each computer in addition to all of the wiringrequired to connect and power each component to the respective computer.Furthermore, additional space is required to house the network interfacecomponents (e.g., a hub or other connection device) and wiring (i.e.,the wiring that physically connects the computers together eitherdirectly or via network interface components). As more equipment isadded to a computer network, it becomes more probable that the spacerequired to house the equipment and associated cabling will exceed thespace allotted for the computer network. Therefore, networkarchitecture, equipment size, and available space are important issueswhen designing an effective computer network environment.

One method of reducing the amount of space required to house a computernetwork is to eliminate user interface devices (i.e., keyboard, videomonitor, mouse, audio output device, audio input device, auxiliaryperipheral devices, etc.) that are not essential for proper operation ofthe computer network. User interface devices, and associated wiring, maybe eliminated if a system administrator is able to access the remotecomputers from the system administrator's computer, thereby eliminatingthe need for dedicated user interface equipment and its associatedwiring.

Allowing a system administrator to operate remote computers or serversfrom the system administrator's computer eliminates the need forphysical relocation of the system administrator to perform systemmaintenance or administration. Also, this capability decreases theamount of space required to house the computer network by eliminatingunnecessary devices.

The following references, which are discussed below, were found torelate to the field of computer management systems: Asprey U.S. Pat. No.5,257,390 (“Asprey '390 patent”), Asprey U.S. Pat. No. 5,268,676(“Asprey '676 patent”), Asprey U.S. Pat. No. 5,353,409 (“Asprey '409patent), Perholtz et al. U.S. Pat. No. 5,732,212 (“Perholtz”), Chen U.S.Pat. No. 5,978,389 (“Chen '389 patent”), Chen U.S. Pat. No. 6,119,148(“Chen '148 patent”), Fujii et al. U.S. Pat. No. 6,138,191 (“Fujii”),Beasley U.S. Pat. No. 6,345,323 (“Beasley”), Pinkston, II et al. U.S.Pat. No. 6,378,009 (“Pinkston”), Thornton et al. U.S. Pat. No. 6,385,666(“Thornton”), Ahern et al. U.S. Pat. No. 6,388,658 (“Ahern”), and Wilderet al. U.S. Pat. No. 6,557,170 (“Wilder”).

The Asprey '390 patent discloses an extended range communications linkfor coupling a computer to a keyboard, video monitor, and/or mouse thatis located remotely from the computer. The end of the link that iscoupled to the computer has a first signal conditioning circuit thatconditions the keyboard, video monitor and mouse signals. Conditioningthe video monitor signals includes reducing their amplitude in order tominimize the amount of “crosstalk” that is induced on the conductorsadjacent to the video signal conductors during transmission of the videosignals. This signal conditioning circuit is coupled to an extendedrange cable having a plurality of conductors that transmits theconditioned signals and power and logic ground potentials to a secondsignal conditioning circuit. This second signal conditioning circuitrestores the video signals to their original amplitude.

The Asprey '676 patent discloses a communications link for use between acomputer and a display unit, such as a video monitor, that allows thesetwo components to be located up to three hundred (300) feet apart. Anencoder located at the computer end of the communications link receivesanalog red, green and blue signals from the computer and inputs eachsignal to a discrete current amplifier that modulates the signalcurrent. Impedance matching networks then match the impedance of thered, green and blue signals to the impedance of the cable and transmitthe signals to discrete emitter-follower transistors located at thevideo monitor end of the cable. These transistors amplify the signalprior to inputting it to the video monitor. Concurrently, the horizontalsynchronization signal is inputted to a cable conductor and itsimpedance is not matched to the impedance of the cable, thereby allowingthe conductor to attenuate the horizontal synchronization signal andreduce noise radiation.

The Asprey '409 patent discloses an extended range communications linkfor transmitting transistor-transistor logic video signals from a localcomputer to a video monitor located up to a thousand (1,000) feet fromthe computer. The link includes a first signal conditioning circuitlocated at the computer end of the link for reducing the amplitude ofthe video signals received from the computer and biasing them to aselected potential, whereafter, they are applied to discrete conductorsof the link. A second signal conditioning circuit receives andreconstructs the transmitted video signals prior to inputting them tothe video monitor. According to the Asprey '409 patent, performance ofthis process reduces the appearance of high frequency video noise on thekeyboard clock conductor of the transmission cable, thereby preventingkeyboard errors. The Chen '389 patent discloses a video signalmultiplexing device for use with a single video monitor that is capableof selecting one video signal from a plurality of computers for displayon the video monitor. The Chen system includes three sets of switchesfor receiving the red, green, and blue components of the video signalsfrom each computer. When a user selects the desired remote computer, aninterface circuit generates a control signal that directs the three setsof switches to select the corresponding video signals from the pluralityof computers. The selected signals are then transmitted to three sets ofswitch circuits and current amplifying circuits that provide input andoutput impedance matching, respectively. The selected video signal isthen displayed on the video monitor.

Perholtz discloses a method and apparatus for coupling a local userworkstation, including a keyboard, mouse, and/or video monitor, to aremote computer. Perholtz discloses a system wherein the remote computeris selected from a menu displayed on a standard size personal computervideo monitor. Upon selection of a remote computer by the system user,the remote computer's video signals are transmitted to the local userworkstation's video monitor. The system user may also control the remotecomputer utilizing the local user workstation's keyboard and monitor.The Perholtz system is also capable of bi-directionally transmittingmouse and keyboard signals between the local user workstation and theremote computer. The remote computer and the local user workstation maybe connected either via the Public Switched Telephone System (“PSTN”)and modems or via direct cabling.

The Chen '148 patent discloses a video signal distributor that receives,processes and distributes video signals received from one or morecomputers to a plurality of video monitors. The video signal distributorincludes three transistor-based voltage amplifying circuits toindividually amplify the red, green and blue video signals received fromeach computer prior to transmitting these signals to a video monitor.The video signal distributor also includes a synchronization signalbuffering device that receives horizontal and vertical synchronizationsignals from each computer and generates new synchronization signalsbased upon the quantity of video signals that are output to the videomonitors.

Fujii discloses a system for selectively operating a plurality ofcomputers that are connected to one common video monitor. The Fujiisystem includes a single interface device for entering data in any oneof the plurality of connected computers. The system also includes a maincontrol circuit, which is connected to the interface device, and aselection circuit for providing the entered data and receiving the videosignals from the selected computer.

Similar to Perholtz, Beasley discloses a specific implementation of acomputerized switching system for coupling a local keyboard, mouseand/or video monitor to one of a plurality of remote computers. Inparticular, a first signal conditioning unit includes an on-screenprogramming circuit that displays a list of connected remote computerson the local video monitor. To activate the menu, a user depresses, forexample, the “print screen” key on the local keyboard. The user selectsthe desired computer from the list using the local keyboard and/ormouse.

According to Beasley, the on-screen programming circuit requires atleast two sets of tri-state buffers, a single on-screen processor, aninternal synchronization generator, a synchronization switch, asynchronization polarizer, and overlay control logic. The first set oftri-state buffers couples the red, green, and blue components of thevideo signals received from the remote computer to the video monitor.That is, when the first set of tri-state buffers are energized, the red,green, and blue video signals are passed from the remote computer to thelocal video monitor through the tri-state buffers. When the first set oftri-state buffers are not active, the video signals from the remotecomputer are blocked. Similarly, the second set of tri-state bufferscouples the outputs of the single on-screen processor to the videomonitor. When the second set of tri-state buffers is energized, thevideo output of the on-screen programming circuit is displayed on thelocal video monitor. When the second set of tri-state buffers is notactive, the video output from the on-screen programming circuit isblocked. Alternatively, if both sets of tri-state buffers are energized,the remote computer video signals are combined with the video signalsgenerated by the on-screen processor prior to display on the local videomonitor.

The on-screen programming circuit disclosed in Beasley also produces itsown horizontal and vertical synchronization signals. To dictate whichcharacters are displayed on the video monitor, the CPU sendsinstructional data to the on-screen processor. This causes the on-screenprocessor to retrieve characters from an internal video RAM for displayon the local video monitor.

The overlaid video image produced by the on-screen processor, namely aMotorola MC141543 on-screen processor, is limited to the size andquantity of colors and characters that are available with the singleon-screen processor. In other words, the Beasley system is designed toproduce an overlaid video that is sized for a standard size computermonitor (i.e., not a wall-size or multiple monitor type video display)and is limited to the quantity of colors and characters provided by thesingle on-screen processor.

During operation of the Beasley system, a remote computer is chosen fromthe overlaid video display. Thereafter, the first signal conditioningunit receives keyboard and mouse signals from the local keyboard andmouse and generates a data packet for transmission to a central crosspoint switch. The cross point switch routes the data packet to thesecond signal conditioning unit, which is coupled to the selected remotecomputer. The second signal conditioning unit then routes the keyboardand mouse command signals to the keyboard and mouse connectors of theremote computer. Similarly, video signals produced by the remotecomputer are routed from the remote computer through the second signalconditioning unit, the cross point switch, and the first signalconditioning unit to the local video monitor. The horizontal andvertical synchronization video signals received from the remote computerare encoded on one of the red, green or blue video signals. Thisencoding reduces the quantity of cables required to transmit the videosignals from the remote computer to the local video monitor.

Pinkston discloses a keyboard, video, mouse (“KVM”) switching systemcapable of coupling to a standard network (e.g., a Local Area Network)operating with a standard network protocol (e.g., Ethernet, TCP/IP,etc.). The system of Pinkston couples a central switch to a plurality ofcomputers and at least one user station having a keyboard, videomonitor, and mouse. The central switch includes a network interface card(“NIC”) for connecting the central switch to a network, which mayinclude a number of additional computers or remote terminals. Utilizingthe Pinkston system, a user located at a remote terminal attached to thenetwork may control any of the computers coupled to the central switch.

Thornton discloses a computer system having remotely located I/Odevices. The system of Thornton includes a computer, a first interfacedevice, and a remotely located second interface device. The firstinterface device is coupled to the computer and the second interfacedevice is coupled to a video monitor and as many as three I/O devices(e.g., keyboard, mouse, printer, joystick, trackball, etc.) such that ahuman interface is created. The first and second interface devices arecoupled to each other via a four wire cable. The first interface devicereceives video signals from the connected computer and encodes thehorizontal and vertical synchronization signals of the received videosignals onto at least one of the red, green, and blue components of thevideo signal. The first interface device also encodes the I/O signalsreceived from the connected computer into a data packet for transmissionover the fourth wire in the four wire cable. Thereafter, the encoded,red, green, and blue components of the video signals and the data packetare transmitted to the second interface device located at the humaninterface. The second interface device decodes the encoded red, green,and blue components of the video signal, separates the encodedhorizontal and vertical synchronization signals, and decodes the I/Osignal data packet. The video signal and the synchronization signals arethen output to the video monitor attached to the second interface andthe decoded I/O signals are routed to the proper I/O device, alsoattached to the second interface. The second interface device mayoptionally include circuitry to encode I/O signals received from the I/Odevices attached to the second interface for transmission to the firstinterface device.

Ahern discloses a switching system for interconnecting a plurality ofcomputer user terminals with a plurality of computers via a computernetwork, thereby allowing a user to access any computer from anycomputer user terminal. Each computer is interfaced to the switchingsystem via a computer interface, which conditions the bi-directionalkeyboard and mouse signals and the uni-directional video signals fortransmission over a single CAT 5 cable to a central switch. The computerinterface also encodes the bi-directional keyboard and mouse signalswith the horizontal and vertical synchronization signals into a datapacket for transmission over one of the twisted pair in the CAT 5 cable.The uni-directional red, green, and blue components of the video signalsare transmitted as analog signals over the remaining three twisted pairin the CAT 5 cable. The central switch contains a series of digitalcross point switches for routing the encoded data packet to the intendeduser interface module, as well as a series of analog cross pointswitches for routing the red, green, and blue components of the videosignals to the same user interface module. Each user interface module isattached to the central switch via a single CAT 5 cable. The userinterface module decodes the bi-directional keyboard and mouse signalsand outputs them to the keyboard and mouse attached to the userinterface. Similarly, the user interface module decodes the horizontaland vertical synchronization signals and outputs the resulting signalsas well as the analog red, green, and blue components of the videosignal to the video monitor attached to the user interface.

Wilder discloses a keyboard, video, mouse and power switching (“KVMP”)apparatus for connecting a plurality of computers to one or more userstations having an attached keyboard, video monitor, and mouse.On-screen display (“OSD”) circuitry embedded within the KVMP switchingapparatus allows a user located at a user station to select and operateany one of the computers utilizing the keyboard, video monitor, andmouse attached to the user station. Secondary switching circuitrylocated within the KVMP switching apparatus allows a user located at auser station to additionally control the electrical power supplysupplying each computer.

In view of the foregoing, a need clearly exists for a multimedia-capableremote computer management system that minimizes expensive,space-consuming, external computer hardware, while providing full accessand control to multiple remote computers. Such a system should alsoallow one or more user workstations to access any one of a plurality ofremote computers and its associated audio and auxiliary peripheraldevices. Furthermore, such a system should greatly enhance the abilityof information technology personnel to manage multiple computers orservers in both small-scale computer centers and large-scale operationssuch as data-centers, server-farms, web-hosting facilities, andcall-centers.

SUMMARY OF THE INVENTION

It is often desirable to allow one or more remote computers to beaccessed and controlled via one or more local sets of peripheral devicesincluding, but not limited to, a keyboard, video monitor, cursor controldevice, audio output device, audio input device and auxiliary peripheraldevices (i.e., serial devices, parallel devices, USB devices, switchcontacts, auxiliary audio channels, etc.). Since the majority ofcomputers in use today are either International Business Machines(“IBM”) computers or clones of an IBM computer, many computers useidentical or similar electrical connectors and communication protocols(e.g., PS/2) to connect a peripheral device to a computer. AnIBM-compatible computer typically contains one type of electricalconnector for each type of peripheral device to which the computer willbe connected. Generally, the cables that interface such peripheraldevices to the respective electrical connector are approximately sixfeet in length, thereby limiting the distance from the computer at whichthe peripheral devices may be located.

In many circumstances, it may be desirable to separate the peripheraldevices from the computer due to space constraints. However, separatinga computer from its peripheral devices is likely to increase cablingcosts. In addition, transmitting signals such as keyboard, video, cursorcontrol device, audio or auxiliary peripheral device signals overdistances greater than fifteen feet is likely to degrade the electricalcharacteristics of the signal resulting in decreased reliability ofkeyboard and cursor control device commands, low quality video andaudio, and degraded auxiliary peripheral device signals. Thisdegradation occurs for a few reasons including the induction of “noise”,or “crosstalk”, between adjacent conductors and an increase in theimpedance encountered by the transmitted signal.

In addition to extending the distance between a computer and itsperipheral devices, it is also convenient to access and operate morethan one computer from one set of peripheral devices. Again, thisfeature is desirable when space is limited and the use of one set ofperipheral devices to control multiple computers eliminates the spacerequired to house a dedicated set of peripheral devices for eachcomputer to be accessed and controlled. Also, the ability to access andcontrol one or more remote computers from one local set of peripheraldevices eliminates the need to physically relocate to the remotecomputer to perform system administration or maintenance for thatcomputer.

The present invention provides an intelligent, modular computermanagement system that enables several simultaneous users to access,control, and operate numerous remote computers and their associatedperipheral devices from one or more sets of local peripheral devices.This computer management system allows a system administrator to accessa remote computer from one set of peripheral devices, preferably locatedat the system administrator's desk, without physically traveling to theremote computer. Furthermore, if the remote computer does not have alocal user, the present invention eliminates the need for a second setof peripheral devices at the remote computer.

The present invention also provides compatibility between variousoperating systems and/or communication protocols. The present inventionallows the same set of local peripheral devices to access and controlremote computers executing a variety of operating systems and protocols,including but not limited to, those manufactured by MicrosoftCorporation (“Microsoft”) (Windows), Apple Computer, Inc. (“Apple”)(Macintosh), Sun Microsystems, Inc. (“Sun”) (Unix), Digital EquipmentCorporation (“DEC”), Compaq Computer Corporation (“Compaq”) (Alpha), IBM(RS/6000), Hewlett-Packard Company (“HP”) (HP9000), and SGI (formerly“Silicon Graphics, Inc.”). Additionally, local devices may communicatewith remote computers via a variety of protocols including, but notlimited to, USB, American Standard Code for Information Interchange(“ASCII”), and Recommend Standard-232 (“RS-232”).

A variety of cabling mechanisms may be used to connect the userworkstations and the remote computers to the computer management systemof the present invention. The preferred embodiment of the presentinvention incorporates a single Category 5 Universal Twisted Pair (“CAT5”) cable to connect each remote computer and each user workstation tothe computer management system. However, other cabling may be usedwithout departing from the spirit of the present invention.

To achieve the desired administration efficiency while reducing costsand promoting space conservation, the present invention provides asystem with reduced cabling requirements. In addition, the architectureof the present invention is designed to minimize the quantity ofperipheral devices associated with each remote computer. Further, it isan object of the present invention to allow audio generated internal toor external to a remote computer to be played at near CD quality at auser workstation.

Therefore, it is an object of the present invention to allow a remotecomputer's auxiliary peripheral devices to be accessed and controlled bya local user workstation.

It is also an object of the present invention to allow bi-directionalcommunication of the auxiliary peripheral device signals between theuser workstation and one or more remote computers.

It is yet another object of the present invention to allow audiogenerated at a user workstation to be played at near CD quality at aremote computer.

Also, it is an object of the present invention to provide an improved,modular computer management system that is reliable while minimizing thequantity of expensive and space-consuming peripheral devices required toaccess and operate multiple remote computers.

Further, it is an object of the present invention to provide a modularcomputer management system that allows one or more sets of peripheraldevices to access and operate one or more remote computers as if thelocal peripheral devices were directly connected to the remotecomputers.

Furthermore, it is an object of the present invention to allowinformation technology (“IT”) personnel to easily manage a volume ofservers for both small-scale computer centers and large-scale computercenters such as data-centers, server-farms, web-hosting facilities, andcall-centers.

Also, it is an object of the present invention to allow IT personnel toeasily communicate with each other when managing two distinct computersseparated by an extended distance.

It is a further object of the present invention to provide a modularcomputer management system that is easy to install and operate.

In addition, it is an object of the present invention to provide amodular computer management system that is relatively small in size,thereby minimizing the space required to house the computers, peripheraldevices and the computer management system.

Furthermore, it is an object of the present invention to provide acomputer management system that allows high resolution video to bedisplayed at an extended distance from the computer at which the videosignals originate.

Further, it is an object of present invention to provide a modularcomputer management system, which allows error-free communicationsbetween peripheral devices of a user workstation and computers locatedat an extended distance from the user workstation.

It is also an object of the present invention to provide a modularcomputer management system that provides enhanced tuning to amplify andcondition video signals after transmission over an extended range.

Other objects, features, and characteristics of the present invention,as well as the methods of operation and functions of the relatedelements of the structure, and the combination of parts and economies ofmanufacture, will become more apparent upon consideration of thefollowing detailed description with reference to the accompanyingdrawings, all of which form a part of this specification.

BRIEF DESCRIPTION OF THE DRAWINGS

A further understanding of the present invention can be obtained byreference to a preferred embodiment and alternate embodiments set forthin the illustrations of the accompanying drawings. Although theillustrated embodiments are merely exemplary of systems for carrying outthe present invention, both the organization and method of operation ofthe invention, in general, together with further objectives andadvantages thereof, may be more easily understood by reference to thedrawings and the following description. The drawings are not intended tolimit the scope of this invention, which is set forth with particularityin the claims as appended or as subsequently amended, but merely toclarify and exemplify the invention.

For a more complete understanding of the present invention, reference isnow made to the following drawings in which:

FIG. 1 is a schematic representation of the remote computer managementsystem according to the preferred embodiment of the present inventionillustrating the connection of multimedia user workstations and multipleremote computers to one Matrix Switching Unit (“MSU”) via CAT 5 cables.

FIG. 2A is a schematic representation is a schematic representation ofthe preferred embodiment of the internal structure of the multimedia USTshown in FIG. 1, including the attached peripheral devices.

FIG. 2B is a detailed schematic diagram of the preferred embodiment ofthe UST transceiver and data converter located within the multimedia USTof FIG. 2A.

FIG. 2C is a schematic representation of the preferred embodiment of thetuning circuit shown in FIG. 2A, which compensates for the amplitude andfrequency reduction that occurs during video signal transmission.

FIG. 3A is a schematic representation of the MSU shown in FIG. 1according to the preferred embodiment of the present inventionillustrating a block diagram of the internal structure of the MSU andelectrical connectors for CAT 5 cables.

FIG. 3B is a detailed schematic diagram of the preferred embodiment ofthe first and second transceivers located within the MSU shown in FIG.3A.

FIG. 4A is a schematic representation of the preferred embodiment of theinternal structure of the multimedia CIM shown in FIG. 1, illustratingconnection of the CIM to a connected computer and to an MSU.

FIG. 4B is a detailed schematic diagram of the preferred embodiment ofthe CIM transceiver and data converter located within the CIM of FIG. 4in accordance with the present invention.

FIG. 5 is a schematic representation of a data packet used to transmitdata in the remote computer management system according to the preferredembodiment of the present invention.

FIG. 6 is a timing diagram showing the transmission of a data packetfrom a multimedia UST to a multimedia CIM via an MSU and from amultimedia CIM to a multimedia UST via an MSU according to the preferredembodiment of the present invention.

FIG. 7 is a schematic representation of an alternate configuration ofthe computer management system for use with the present inventionillustrating connection of multiple user workstations and multipleconnected computers to multiple MSUs, wherein the alternate embodimentmay accommodate as many as sixty-four (64) user workstations and tenthousand (10,000) connected computers.

FIG. 8 is a schematic representation of an alternate embodiment of thecomputer management system of the present invention, wherein thecomputer management system is contained in a single unit that isdirectly connected to all connected computers and user workstations.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

As required, detailed illustrative embodiments of the present inventionare disclosed herein. However, techniques, systems and operatingstructures in accordance with the present invention may be embodied in awide variety of forms and modes, some of which may be quite differentfrom those in the disclosed embodiment. Consequently, the specificstructural and functional details disclosed herein are merelyrepresentative, yet in that regard, they are deemed to afford the bestembodiment for purposes of disclosure and to provide a basis for theclaims herein, which define the scope of the present invention. Thefollowing presents a detailed description of the preferred embodiment(as well as some alternative embodiments) of the present invention.

Referring first to FIG. 1, depicted is the architecture of the preferredembodiment of the present invention. Specifically, a modular,intelligent, computer management system is shown including a centrallylocated MSU 112, multimedia user workstations 100, multimedia CIMs 116,CIM audio output devices 126, CIM audio input devices 128, CIM I/Omodules 130, and remote computers 118. Each multimedia user workstation100 comprises multimedia UST 108, keyboard 102, video monitor 104,cursor control device 106, UST audio output device 120, UST audio inputdevice 122, and UST I/O module 124. Furthermore, each multimedia UST 108and multimedia CIM 116 is connected to MSU 112 via cables 110 and 114,respectively. Although the computer management system is discussedherein with respect to the multimedia embodiment of the presentinvention, it should be noted that the present invention is also capableof operating with non-multimedia USTs and non-multimedia CIMs.

Although single CAT 5 cabling is the preferred cabling for use with thepresent invention, other cabling may be used, such as coaxial, fiberoptic, or multiple CAT 5 cables, depending on the specific needs of thesystem user. CAT 5 cabling is preferred because it reduces cabling costswhile maintaining the strength of the signals that are transmitted overextended distances. Additionally, the use of single CAT 5 cablingminimizes the space required to house the computer system and itsassociated wiring.

Individual CAT 5 cables may be used for connection of each multimediaUST 108 and each multimedia CIM 116 to MSU 112. Conventional CAT 5cables include four (4) twisted pair of wires. The present inventionutilizes three (3) of these twisted pair for the transmission of videosignals. Each of the three (3) twisted pair transmits one of the threevideo color signals (i.e., red, green or blue). To allow all videosignals to be transmitted via only (3) twisted pair, the horizontal andvertical synchronization signals, which would otherwise require theirown twisted pairs, are individually encoded on one of the red, green, orblue video signals. That is, each synchronization signal is encoded onits own, dedicated color signal. For example, the verticalsynchronization signal may be encoded on the blue video signal while thehorizontal synchronization signal may be encoded on the green videosignal. All other non-video signals such as keyboard, cursor controldevice, and audio signals, are transmitted via the fourth twisted paircable.

The single CAT 5 cables are connected to multimedia UST 108, MSU 112,and multimedia CIM 116 by plugging each end into a RJ-45 connectorlocated on these respective components. Although RJ-45 connectors arepreferred, other types of connectors may be used, including but notlimited to RJ-11, RG-58, RG-59, British Naval Connector (“BNC”), and STconnectors.

UST audio output device 120 and CIM audio output device 126 of thepresent invention may be any device that is capable of receiving audiosignals. For example, UST audio output device 120 and CIM audio outputdevice 126 may be the audio in port of remote computer 118, a speaker,an analog recording device, a digital recording device, anaudio-equipped projector, an audio-equipped camcorder, an audio-equippedcamera, a television, a telephone, a cellular telephone, a computerdistinct from remote computer 118, etc. Similarly, UST audio inputdevice 122 and CIM audio input device 128 may be any device that iscapable of generating or transmitting audio signals. For example, USTaudio input device 122 and CIM audio input device 128 may be the audioout port of remote computer 118, a microphone, an analog playbackdevice, a digital playback device, an audio-equipped projector, anaudio-equipped camcorder, an audio-equipped camera, a telephone, acellular telephone, a television, a Videocassette Recorder (“VCR”), aDVD player, a CD-player, a computer distinct from remote computer 118,etc.

UST I/O module 124 and CIM I/O module 130 of the present invention areused to connect auxiliary peripheral devices to the multimedia UST 108and multimedia CIM 116, respectively. UST I/O module 124 and CIM I/Omodule 130 may contain one or more ports of varying types for connectionof auxiliary peripheral devices. The types of ports include, but are notlimited to, Universal Serial Bus (“USB”), Recommended Standard 232(“RS-232”), PS/2, Registered Jack 11 (“RJ-11”), Registered Jack 31(“RJ-31”), Registered Jack 45 (“RJ-45”), Registered Jack 48 (“RJ-48”),British Naval Connector (“BNC”), Centronics, Advanced Technology (“AT”),Super Video (“S-Video”), Digital Video Interface (“DVI”), IntegratedDevelopment Environment (“IDE”), Fiber Distributed Data Interface(“FDDI”), Small Computer System Interface (“SCSI”), and switch contact.

Various types of auxiliary peripheral devices may be connected to USTI/O module 124 and CIM I/O module 130. Some examples of auxiliaryperipheral devices include, but are not limited to, a keyboard, a cursorcontrol device, an optical cursor control device, a trackball, a USBkeyboard/cursor control device adapter, a port expander, a Bluetoothdevice, a cellular telephone, a web camera, a floppy disk drive, a harddisk drive, a USB Flash Drive, a digital media reader/writer, amicrophone, a speaker, a subwoofer, a scanner, a copier, a printer, aprojector, a television, an analog monitor, a digital monitor, a videocapture device, a modem, a hub, a router, a switch, a cable modem, a DSLmodem, a wireless network hub, a wireless network router, a wirelessaccess point, a print server, a wireless print server, an Ethernetadapter, an analog audio playback device, an analog audio recordingdevice, a digital audio playback device, a digital audio recordingdevice, a tape drive, a storage backup device, a joystick, a game pad, apower supply, an uninterruptible power supply (“UPS”), a USB hub, aCD-ROM device, a CD-RW device, a DVD-ROM device, a DVD-RAM device, acamera, a camcorder, a fingerprint reader, a retina scanner, and abiometric authentication device.

Each auxiliary peripheral device may either be coupled to multimedia UST108 via UST I/O module 124 or to multimedia CIM 116 via CIM I/O module130. For example, a CD-ROM device may be attached to a multimedia UST108 to allow a system administrator to perform software upgrades. Thesystem administrator can then access and upgrade each remote computerutilizing the CD-ROM device attached to the system administrator'smultimedia UST 108. As another example, a tape drive may be attached toa multimedia UST 108 to allow a system administrator to backup multiplecomputers from the same multimedia user workstation 100 utilizing asingle tape drive.

Additionally, auxiliary peripheral devices may be used for securitypurposes. For example, a fingerprint reader may be attached to amultimedia user workstation 100 to read the identity of the individualattempting to operate it. The system may be programmed to only allow asystem administrator to access and operate remote computer 118 uponfingerprint authentication by the respective remote computer 118. Inthis manner, user access to each remote computer 118 may be controlledby verifying the identity of the user.

Similarly, any of the aforementioned auxiliary peripheral devices may beattached to multimedia CIM 116. For example, a microphone may beattached to multimedia CIM 116 to allow voice communication between aperson located at multimedia CIM 116 and a person located at multimediauser workstation 100. This capability greatly enhances the systemadministration of remote computers 118 by allowing a systemadministrator located at multimedia CIM 116 to more effectivelycommunicate with another system administrator located at multimedia userworkstation 100.

The aforementioned examples are for illustrative purposes only and arenot intended to define all of the embodiments of the present invention.Many other combinations of auxiliary peripheral devices are possiblewithout departing from the spirit of the present invention.

Each multimedia user workstation 100 of the intelligent, modularcomputer management system of the present invention receive signals fromattached keyboard 102, cursor control device 106, UST audio outputdevice 120, UST audio input device 122, and UST I/O module 124. Thesignals received at multimedia UST 108 are packetized (i.e., convertedto one or more data packets), as discussed in greater detail below, andtransmitted to MSU 112 via single cable 110. In the preferredembodiment, the data packets are also encoded utilizing Manchester code.Manchester code is a standard code used to transmit data in which dataand clock signals are combined to form a single self-synchronizing datastream. Manchester encoding guarantees that there are transitions in thesignal for every bit transmitted, thus allowing for better data recoveryin long length cables. At MSU 112, the packetized signals are processedto create new data packets, which are transmitted to multimedia CIM 116via cable 114. Multimedia CIM 116 then processes the received datapackets and emulates keyboard and cursor control device signals to thecorresponding ports of remote computer 118. Additionally, multimedia CIM116 is capable of emulating audio to CIM audio output device 126 orauxiliary peripheral device signals to CIM I/O module 130.

Conversely, multimedia CIM 116 receives signals from attached remotecomputer 118, CIM audio input device 128, and CIM I/O module 130.Specifically, the signals received from remote computer 118 includekeyboard, video, and cursor control device signals. Multimedia CIM 116then packetizes the received keyboard, cursor control device, audio, andauxiliary peripheral device signals and transmits the generated datapackets along with the video signals, as discussed in greater detailbelow, to MSU 112 via cable 114. At MSU 112, the data packets areprocessed and new data packets are generated and transmitted along withthe video signals to multimedia UST 108 via single cable 110. MultimediaUST 108 then applies the received video signals to attached videomonitor 104 and emulates keyboard and cursor control device signals tokeyboard 102 and cursor control device 106, respectively. Also,multimedia UST 108 is capable of emulating audio to attached UST audiooutput device 120 and emulating auxiliary peripheral device signals toUST I/O module 124.

The computer management system of the present invention allows a systemuser to select a remote computer 118 even if it is not powered. Thisnovel feature allows a system user to select the unpowered remotecomputer 118, apply power to it, and thereafter view its boot upsequence. Viewing the boot up sequence allows a system user to view allBIOS (i.e., a set of routines stored in the PC that provides aninterface between the PC hardware and its operating system) activityoccurring from the time at which power is applied.

Furthermore, for simplicity, FIG. 1 depicts an embodiment of thecomputer management system of the present invention that connects eight(8) multimedia USTs 108 and thirty-two (32) multimedia CIMs 116 to oneMSU 112. However, the computer management system of the presentinvention may comprise more than one MSU 112. For example, multiple MSUs112 may be configured in a tiered or hub configuration to connect avirtually unlimited quantity of multimedia user workstations 100 with avirtually unlimited quantity of remote computers 118 while stillachieving optimal results. Two alternate configurations are discussed ingreater detail below with respect to FIGS. 7 and 8.

Selection of remote computer 118 from multimedia user workstation 100may be accomplished using a variety of methods. One such method ischoosing remote computer 118 from a list displayed at video monitor 104.This list is generated by a menu circuit embedded within the computermanagement system. The menu circuit generates a display on video monitor104 to facilitate system programming and provide information that isuseful for system operation. Furthermore, multiple security featuressuch as passwords, system user histories, etc. may be implemented andoperated in conjunction with the menu circuit and its generated display.

The list generated by the computer management system of the presentinvention includes a “drill down” feature. In other words, the computermanagement system may be configured to allow a system user to select ashort list of remote computers 118 based upon specific criteria (e.g.,the function performed by the computer, the server rack or server roomin which the computer is located, the floor of the building on which thecomputer is located, etc.) in lieu of scrolling through a list of allconnected remote computers 118. Since the computer management system ofthe present invention may connect a virtually unlimited quantity ofremote computers, this feature helps a system user to quickly locate asingle computer.

Turning next to FIG. 2A, depicted is a schematic diagram of thepreferred internal structure of multimedia UST 108 according to thepresent invention. Multimedia UST 108 interfaces the components ofmultimedia user workstation 100 (i.e., keyboard 102, video monitor 104,cursor control device 106, UST I/O module 124, UST audio output device120, and UST audio input device 122) for use with the computermanagement system of the present invention. Keyboard 102, video monitor104, cursor control device 106, UST audio output device 120, and USTaudio input device 122 are connected to keyboard port 300, video port312, cursor control device port 310, UST audio out port 320, and USTaudio in port 322 of multimedia UST 108, respectively, using industrystandard keyboard, video, cursor control device, and audio cabling. Inthe preferred embodiment of the present invention, UST I/O module 124 isconnected to UST I/O port 318 via a 40-pin ribbon cable. However, itwill be apparent to one of skill in the art that multimedia UST 108 andUST I/O module 124 can be designed to utilize any type of cable forcoupling multimedia UST 108 to UST I/O module 124 including, but notlimited to, coaxial cable, fiber optic cable, CAT 1 cable, CAT 2 cable,CAT 3 cable, CAT 4 cable, CAT 5 cable, CAT 5e cable, CAT 6 cable, andCAT 7 cable. Furthermore, UST I/O module 124 may be a standalone deviceor may be internal to multimedia UST 108.

UST CPU 308 receives signals from keyboard 102 and cursor control device106 via keyboard port 300 and cursor control device port 310,respectively. Thereafter, UST CPU 308 transmits information to USTtransceiver 306 via data converter 324 to allow the information to beincluded in a data packet to be created by UST transceiver 306.

Simultaneously, data converter 324 receives signals from UST I/O module124 and UST audio input device 122 via UST I/O port 318 and UST audio inport 322, respectively. Additionally, signals relating to the keyboardand cursor control device information are received from UST CPU 308 forinclusion in the data packet. UST transceiver 306 combines the receivedkeyboard signals, cursor control device signals, audio signals, I/Omodule signals, and administrative signals to create data packets.

As shown in FIG. 2B, which depicts a schematic diagram of USTtransceiver 306 and data converter 324, the UST I/O module signals arereceived from UST I/O module 124 via UST I/O port 318 and are input tobit converter 350 located in data converter 324. Bit converter 350translates UST I/O module signals into a parallel data format.Similarly, the audio signals are received from UST audio input device122 via UST audio in port 322 and are converted to digital signals byanalog-digital converter (“AD converter”) 352. The digitized audiosignals are then input to audio rate converter 354 which formats therate of data flow. Additionally, signals relating to the keyboard andcursor control device information are received from UST CPU 308 and areinput to serial rate converter 356 which converts the keyboard andcursor control device signals to a serial format.

UST transceiver 306 combines the signals received from audio rateconverter 354, serial rate converter 356, and bit converter 350 tocreate data packets in packetizer 358, as discussed in further detailbelow with respect to FIG. 5. It should be noted that the I/O modulesignals typically contain the same information as the auxiliaryperipheral device signals mentioned above. The reason for this is thatUST I/O module 124 and CIM I/O module 130 are used to interfaceauxiliary peripheral devices to multimedia UST 108 and multimedia CIM116, respectively. In addition, the data packet contains overhead data,also discussed in more detail below for FIG. 5. Thereafter, USTtransceiver 306 converts the data packets to a serial format utilizingserializer 360 and encodes the data packet utilizing encoder 362. Signalconverter 364 then conditions the data packet for transmission over asingle CAT 5 cable by converting the data packet to a differentialsignal for transmission over a single twisted pair located in the CAT 5cable and by applying the proper network protocol to the data packet.The data packet is then transmitted to port 302 for transmission to MSU112 via cable 110. Timing circuit 366 directs serializer 360 and signalconverter 364 to create and transmit a new data packet every twenty (20)microseconds to ensure constant data flow.

Keyboard, cursor control device, I/O module, and audio signals in theform of a data packet are received from MSU 112 via cable 110 at port302. Signal converter 364 located in UST transceiver 306 converts thedata packet from a differential form to its original form and removesnetwork protocol conditioning performed by MSU 112. Next, the datapacket is decoded by decoder 368 and de-serialized by de-serializer 370.Timing circuit 366 instructs de-serializer 370 to de-serialize a datapacket every twenty (20) microseconds to ensure constant data packetflow. The data packet is then processed by separator 372 which parsesthe data packet into its original components.

The received audio signals are processed by audio rate converter 374located in data converter 324. Audio rate converter 374 synchronizes andconverts the received data rate to precisely timed data required byaudio digital-to-analog converter 376. The digital audio signals arethen converted to analog signals in audio digital-to-analog converter(“DAC converter”) 376 and undergo signal amplification by signalamplifier 378. The amplified analog audio signals are then applied toUST audio out port 320.

The received I/O module signals are conditioned by bit shifter 380 whichconverts the I/O module signals from a parallel format to their originalformat. The I/O module signals are then transmitted to UST I/O module124 via UST I/O module port 318. The keyboard and cursor control devicesignals are processed by rate converter 382 and passed through dataconverter 324 to UST CPU 308, which uses the information contained inthe signals to emulate keyboard and cursor control device signals. Theseemulated signals are applied to keyboard 102 and cursor control device106 via keyboard port 300 and cursor control device port 310,respectively (FIG. 2A).

Referring to FIG. 5, provided is an example of a data packet used totransmit keyboard, cursor control device, audio, and auxiliaryperipheral device signals in accordance with the preferred embodiment.The system of the present invention utilizes the same data packetstructure to transmit keyboard signals, cursor control device signals,audio signals, and auxiliary peripheral device signals from multimediaCIM 116 to multimedia UST 108 and vice versa. The preferred embodimentof data packet 500 consists of sixty-four (64) bits. First section 502comprises two bits that contain instructional data (i.e., command data)and data regarding the total length of data packet 500.

Second section 504 of data packet 500 comprises thirty-four (34) bitsand is dedicated to the transmission of audio data. Sixteen (16) bitsare utilized for the left stereo audio channel and sixteen (16) bits areutilized for the right stereo audio channel. The remaining two bits ofsecond section 504 are checksum bits that are used to ensure that theaudio data is transmitted without error.

Third section 506 of data packet 500 comprises ten (10) bits and isdedicated to the transmission of keyboard, cursor control device, andadministrative information including characters typed on keyboard 102 orclicks performed with cursor control device 106 (FIG. 1). Eight (8) ofthe ten (10) bits are utilized to transmit the keyboard, cursor controldevice, and administrative information, one bit is used as a parity bitfor use in a parity check, and the final bit is utilized as a controlbit. The control bit is used to signal if data is present in the datapacket. The control bit is additionally utilized to select if the datapacket is transmitted to MSU CPU 212.

Fourth section 508 of data packet 500 comprises the remaining eighteenbits of data packet 500 and is utilized to transmit auxiliary peripheraldevice signals such as those received from CIM I/O module 130 or UST I/Omodule 124.

Multimedia UST 108 continuously transmits one data packet 500approximately every twenty five (25) microseconds, even if multimediaUST 108 is not connected to the computer management system.Additionally, for simplicity, there is no packet acknowledge. That is,multimedia UST 108 and multimedia CIM 116 do not transmit anacknowledgement signal to multimedia CIM 116 or multimedia UST 108,respectively, to acknowledge that a data packet has been received.

As each data packet 500 is received at MSU 112, it is received andprocessed and, thereafter, a new data packet 500 is created, asdiscussed above with respect to FIG. 2A. During processing of datapacket 500, MSU 112 creates a new third section 506 of data packet 500.The remainder of data packet 500 (i.e., first section 502, secondsection 504, and fourth section 508) is passed through MSU 112 withoutchange.

Similarly, keyboard, cursor control device, I/O module, and audiosignals received from MSU 112 via cable 110 (FIG. 1) are received viaport 302. UST transceiver 306 receives, de-serializes, and transmitsthese signals to data converter 324. The received audio signals areconverted to analog signals and are applied to UST audio output device120 via UST audio out port 320. The received I/O module signals areconverted and transmitted TO UST I/O module 124 via UST I/O module port318. The keyboard and cursor control device signals are passedunprocessed through data converter 324 to UST CPU 308, which uses theinformation contained in the signals to emulate keyboard and cursorcontrol device signals to keyboard 102 and cursor control device 106 viakeyboard port 300 and cursor control device port 310, respectively.

UST CPU 308 of the present invention is programmed to automaticallycreate keyboard and cursor control device signals that are compatiblewith the communication protocol of the connected keyboard 102 and cursorcontrol device 106, even though the original keyboard and cursor controldevice signals generated at the remote computer 118 (FIG. 1) may not becompatible with the communication protocol of keyboard 102 and cursorcontrol device 106. That is, the keyboard and cursor control devicesignals are not simply transmitted from keyboard 102 and cursor controldevice 106 to the respective ports of remote computer 118 and viceversa. Rather, information regarding the entered signals is transmittedbetween UST CPU 308 and CIM CPU 406 (FIG. 4A), and these CPUsintelligently emulate the keyboard and cursor control device signals ina format that will be understood by the equipment receiving the signals(i.e., keyboard 102, cursor control device 106, or remote computer 118).This novel feature allows any type of computer to be connected to thecomputer management system of the present invention. Furthermore, thisfeature allows the computer management system to provide compatibilitybetween computers and auxiliary peripheral devices that otherwise wouldnot be compatible.

Unidirectional video signals are also received at port 302 from MSU 112via cable 110 (FIG. 1). However, because the amplitudes of thetransmitted signals are greatly reduced and the frequencies of thesignals are attenuated, the video signals are not transmitted to USTtransceiver 306, but rather are transmitted to tuning circuitry 304 thatconditions the video signals. FIG. 2C depicts a schematic representationof tuning circuitry 304. Tuning circuitry 304 preferably comprises redvariable gain amplifier 710 a, green variable gain amplifier 710 b, bluevariable gain amplifier 710 c, red frequency compensation amplifier 712a, green frequency compensation amplifier 712 b, blue frequencycompensation amplifier 712 c, slow peak detector 714, voltage source716, comparator 718, slow peak detector 724, voltage source 726,comparator 728, video switch 730, fast peak detector 732, and comparator734.

During operation, the keyboard, video, and cursor control device signalsfrom remote computer 118 are transmitted via cable 418 to CIM 116 (FIGS.1 and 4). Thereafter, the video signals and data packets generated byCIM CPU 406 are transmitted from CIM 116 to MSU 112 via CAT 5 cable 114(FIGS. 1 and 4). At this point in the video signal transmission, theamplitudes of the transmitted video signal may be greatly reduced andthe frequencies of the video signal may be attenuated. Subsequently, thevideo signal and the signals generated by MSU CPU 212 are transmittedfrom MSU 112 to UST 108, wherein the video signal is conditioned bytuning circuitry 304.

As previously discussed, the video signal is degraded duringtransmission over an extended range. Specifically, the amplitudes of thevideo signals are reduced and the frequencies of the video signals aregreatly attenuated. Therefore, tuning circuitry 304 is implemented toautomatically tune the received signals to achieve the desired amplitudeand frequency.

In the preferred embodiment, the horizontal synchronization signal isencoded on and transmitted with the green video signal, and the verticalsynchronization signal is encoded on and transmitted with the blue videosignal. However, it is known to one of ordinary skill in the art thatthe horizontal and vertical synchronization signals may be encoded onand transmitted with any one of the red, green, or blue video signals.Preferably, the horizontal and vertical synchronization signals areencoded as negative pulses, since the video signals (i.e., red, green,and blue) are typically positive pulses.

Tuning circuitry 304, as depicted in FIG. 2C, contains three dedicatedsignal conditioning circuits (i.e., one for each of the red, blue, andgreen video color signals), a gain amplification adjustment circuit 715,a frequency compensation amplification adjustment circuit 735, and anadditional filtering enablement circuit 725.

In operation, the red component of the video signal is initiallytransmitted to red variable gain amplifier 710 a and red variablefrequency compensation amplifier 712 a. Preferably, red variable gainamplifier 710 a adjusts the amplitude of the red component of the videosignal based upon the output of gain amplification adjustment circuit715. Concurrently, red variable frequency compensation amplifier 712 aadjusts the frequency of the red component of the video signal basedupon the output of frequency compensation amplification adjustmentcircuit 735. The outputs of red variable gain amplification circuit 710a and red frequency compensation circuit 712 a are electrically combinedand transmitted via wire 722 to video port 312 for transmission to videomonitor 104.

The green component of the video signal, with the encoded horizontalsynchronization signal, is initially transmitted to green variable gainamplifier 710 b and green variable frequency compensation amplifier 712b. The two outputs are then electrically combined and transmitted togain amplification adjustment circuit 715 and frequency compensationamplification adjustment circuit 735. Gain amplification circuit 715comprises slow peak detector 714 that receives the electrically combinedoutputs of green variable gain amplifier 710 b and green variablefrequency compensation amplifier 712 b. Slow peak detector 714 detectsthe amplitude of the horizontal synchronization signal, which is encodedon the green component of the video signal, and transmits a signalrepresenting this amplitude to comparator 718 and comparator 734.Comparator 718 then compares the signal received from slow peak detector714 to a constant reference voltage supplied by voltage source 716. Thesignal supplied by voltage source 716 represents the desired amplitudefor the horizontal synchronization signal. Next, comparator 718transmits a signal to red variable gain amplifier 710 a, green variablegain amplifier 710 b, and blue variable gain amplifier 710 c to adjustthe level of amplification of the red, green, and blue components of thevideo signal until the desired amplitude is achieved.

Similarly, green variable frequency compensation amplifier 712 b adjuststhe level of amplification of the frequency of the horizontalsynchronization signal based upon the output of frequency compensationamplification adjustment circuit 735. Frequency compensationamplification adjustment circuit 735 comprises fast peak detector 732that also receives the electrically combined outputs of green variablegain amplifier 710 b and green variable frequency compensation amplifier712 b. Fast peak detector 732 detects the rising edge of the horizontalsynchronization signal and transmits a signal representing this risingedge to comparator 734. Then, comparator 734 compares the signalreceived from fast peak detector 732 to the output of slow peak detector714 to compare the amplitude of the rising edge of the horizontalsynchronization signal pulse to the amplitude of the horizontalsynchronization signal pulse itself. Next, comparator 734 sends a signalthat is fed to red variable frequency compensation amplifier 712 a,green variable frequency compensation amplifier 712 b, and blue variablefrequency compensation amplifier 712 c to adjust the level ofamplification of the red, green, and blue components of the video signaluntil the desired frequency is achieved. optionally, the signaltransmitted by comparator 734 may be manually adjusted using manualinput 733 by a system user (e.g., via the menu displayed on the videomonitor). Such a feature would allow the system user to manually “tweak”the gain of the video signals until a desired video output is achieved.

The blue component of the video signal, along with the encoded verticalsynchronization signal, is initially transmitted to blue variable gainamplification circuit 710 c, blue variable frequency compensationcircuit 712 c, and filtering enablement circuit 725, which is employedto increase the range of red variable frequency compensation amplifier712 a, green variable frequency compensation amplifier 712 b, and bluevariable frequency compensation amplifier 712 c when the video signalshave been transmitted over approximately four hundred fifty (450) feet.The vertical synchronization signal, which is encoded on the bluecomponent of the video signal as a precise square wave signal of knownduration and amplitude, is used as a precise reference point forfiltering enablement circuit 725. The blue component of the video signaland the encoded vertical synchronization signal are received by slowpeak detector 724, which detects the amplitude of the verticalsynchronization signal. Slow peak detector 724 transmits a signalrepresenting the amplitude of the vertical synchronization signal tocomparator 728, which compares it to the known amplitude of a similarsignal transmitted for four hundred fifty (450) feet. This knownamplitude is represented by a constant reference voltage applied tocomparator 728 by voltage source 726. If comparator 728 determines thatthe vertical synchronization signal (and therefore all of the videosignals) have been transmitted over four hundred fifty (450) feet, asignal indicating this is transmitted to video switch 730. Video switch730 then sends a signal to red variable frequency compensation amplifier712 a, green variable frequency compensation amplifier 712 b, and bluevariable frequency compensation amplifier 712 c to increase the range ofeach frequency compensation amplifier 712 a, 712 b, and 712 c.Subsequent to gain amplification by gain amplification adjustmentcircuit 715 and frequency compensation by frequency compensationamplification adjustment circuit 735, the conditioned red, green, andblue components of the video signal are transmitted to video monitor 104of the local user workstation via wire 722 and video port 312.

Turning next to FIG. 3A, depicted is a schematic representation of MSU112, which enables multiple users operating multimedia user workstations100 to access and operate multiple remote computers 118. In thepreferred embodiment of the present invention, access to remote computer118 from multimedia user workstation 100 is performed solely via one ormore MSUs 112, independent of any network that may couple the remotecomputers 118 to each other such as a LAN, WAN, etc. In other words, thepreferred embodiment of the computer management system of the presentinvention does not use an existing computer network to allow amultimedia user workstation 100 to access and control remote computers118. Rather, all physical connections between multimedia userworkstation 100 and remote computer 118 occur through one or more MSUs112.

In the preferred embodiment of the present invention, each port 202 isan RJ-45 socket that allows one multimedia CIM 116 to be connected toits own, dedicated port 202 via cable 114 (FIG. 1). Theuni-directionally transmitted (i.e., from remote computer 118 tomultimedia user workstation 100 only) video signals are received at MSU112 via port 202 onto video bus 222, whereupon these signals aretransmitted to video differential switch 206. Video differential switch206 is capable of routing any video signal received from video bus 222to any port 216. Therefore, video differential switch 206 transmits thevideo signals to the specific port 216 that is connected to the desiredmultimedia UST 108 via single cable 110 (FIG. 1). Multimedia UST 108then applies the received video signals to video monitor 104.

In addition to routing the unidirectional video signals, MSU 112 alsobi-directionally transmits keyboard, cursor control device,administrative, audio and auxiliary peripheral device signals betweenmultimedia USTs 108 and multimedia CIMs 116. Administrative signals aresignals created internal to the computer management system of thepresent invention based upon the input of a system administrator or asystem programmer. In the preferred embodiment of the present invention,such input is provided via keyboard 102 and cursor control device 106 ofmultimedia user workstation 100 in response to a menu displayed on videomonitor 104. One such administrative feature allows a systemadministrator to designate one or more remote computers 118 as blocked(i.e., only the system administrator may access the remote computer 118and all other system users are blocked from accessing it). Anothersimilar feature allows the system administrator to deactivate a userprofile without deleting it. Both of these features allow the systemadministrator to modify access to remote computers and modify userprofiles with simple commands in lieu of physical disconnection ofremote computers 118 or regeneration of user profiles.

When routing the keyboard, cursor control device, administrative, audioand auxiliary peripheral device signals from multimedia CIM 116 tomultimedia UST 108, these signals are received from multimedia CIM 116in the form of a data packet, as illustrated in FIG. 5, through ports202 onto peripheral bus 220. Thereafter, the data packets aretransmitted to peripheral switch 214, which transmits the received datapacket to the appropriate first transceiver 241. First transceiver 241then transmits the signals to MSU central processing unit (“CPU”) 212for processing. MSU CPU 212 processes the received data packet andgenerates a new data packet.

As shown in FIG. 3B, which depicts a schematic diagram of the preferredembodiment of first transceiver 241 and second transceiver 230, the datapacket arrives from peripheral switch 214 at signal converter 250 whichconverts the data packet from a differential form to its original form.The data packet is then transmitted to decoder 252 (preferably aManchester decoder) which decodes the encoded data packet. After thedata packet has been processed by decoder 252, the data packet isde-serialized by de-serializer 254 which converts the serial stream ofbits in the data packet into parallel streams of bits. Command extractor256 then processes the de-serialized data packet to remove the portionof the data packet relating to keyboard, cursor control device, andadministrative signals. MSU CPU 212 utilizes the removed portion of thedata packet to determine the proper second transceiver 230 to which totransmit the remainder of the data packet.

The remainder of the data packet is then transmitted from commandextractor 256 to command combiner 258 located in second transceiver 230as determined by MSU CPU 212. Command combiner 258 appends a new set ofkeyboard, cursor control device, and administrative signals created byMSU CPU 212 to the data packet received from command extractor 256. Thedata packet is then serialized by serializer 260 and encoded by encoder262. Next, signal converter 264 conditions the data packet fortransmission over a single CAT 5 cable by converting the data packet toa differential signal for transmission over a single twisted pairlocated in the CAT 5 cable and by applying the proper network protocolto the data packet. The data packet is then transmitted to port 216.Alternatively, under software control, the entire data packet may betransmitted from command extractor 256 to command combiner 258 withoutpassing through MSU CPU 212 as previously described (shown as dottedline arrow). When in this “by-pass” mode of operation, the data packetis still being sent to MSU CPU 212.

Similarly, data packets containing encoded keyboard, cursor controldevice, administrative, audio, and auxiliary peripheral device signalsare also transmitted to peripheral switch 214 from port 216 utilizingfirst transceiver 241 and second transceiver 230. In this scenario, thedata packet arrives from port 216 at signal converter 264 located insecond transceiver 230 which converts the data packet from adifferential form to its original form. Signal converter 264 alsoremoves network protocol conditioning which occurs when the data packetis transmitted over a single CAT 5 cable. The data packet is thentransmitted to decoder 266. After the data packet has been processed bydecoder 266, the data packet is de-serialized by de-serializer 268.Command extractor 270 then processes the de-serialized data packet toremove the portion of the data packet relating to keyboard, cursorcontrol device, and administrative signals. MSU CPU 212 utilizes theremoved portion of the data packet to determine the proper firsttransceiver 241 to which to transmit the remainder of the data packet.Alternatively, under software control, the entire data packet may betransmitted from command extractor 270 to command combiner 272 withoutpassing through MSU CPU 212 as previously described.

The remainder of the data packet is then transmitted from commandextractor 270 to command combiner 272 located in first transceiver 241as determined by MSU CPU 212. Command combiner 272 appends a new set ofkeyboard, cursor control device, and administrative signals created byMSU CPU 212 to the data packet received from command extractor 270. Thedata packet is then serialized by serializer 274 and encoded by encoder276. Next, signal converter 250 conditions the data packet fortransmission over a single CAT 5 cable by converting the data packet toa differential signal for transmission over a single twisted pairlocated in the CAT 5 cable and by applying the proper network protocolto the data packet. The data packet is then transmitted to peripheralswitch 214.

Thereafter, the information pertaining to the new data packet istransmitted to the appropriate second transceiver 230 which creates andserializes the data packet and transmits it to port 216 for transmissionvia single cable 110 to the desired multimedia UST 108 (FIG. 1).Multimedia UST 108 then processes the data packet and emulates keyboard,cursor control device, audio, and auxiliary peripheral device signals tokeyboard 102, cursor control device 106, UST audio output device 120,and UST I/O module 124, respectively (FIG. 1).

Similarly, MSU 112 also transmits keyboard, cursor control device,administrative, audio, and auxiliary peripheral device signals frommultimedia USTs 108 to multimedia CIMs 116 (FIG. 1). In this scenario,these signals are received at multimedia UST 108 from the respectiveconnected devices, wherein information relating to the received signalsis packetized and transmitted via cable 110 to the port 216 located atMSU 112. Thereafter, the data packet is transmitted to secondtransceiver 230, which de-serializes it and transmits it to MSU CPU 212.MSU CPU 212 interprets the information contained in the data packet andcreates information to be contained in a new data packet, as discussedabove. The information relating to the new data packet is thentransmitted to the specific first transceiver 241 that is associatedwith the desired remote computer 118. First transceiver 241 creates andserializes the data packet and transmits it to peripheral switch 214,which transmits the data packet to the desired port 202 via peripheralbus 220. Subsequently, the data packet is transmitted via cable 114 tothe specific multimedia CIM 116 that is connected to the desired remotecomputer 118 (FIG. 1). Multimedia CIM 116 processes the data packet andemulates the keyboard, cursor control device, audio, and auxiliaryperipheral device to the corresponding devices.

Turning next to FIG. 4A, shown is a schematic diagram of the interior ofmultimedia CIM 116. Multimedia CIM 116 is compatible with all presentday computer systems including, but not limited to, those manufacturedby Microsoft (Windows), Apple (Macintosh), Sun (Unix), DEC, Compaq(Alpha), IBM (RS/6000), HP (HP9000), and SGI. However, it is foreseeablethat the technology of the present invention will also be compatiblewith those computer systems not yet contemplated.

Multimedia CIM 116 interfaces video port 412, keyboard port 414, andcursor control device port 416 of remote computer 118 to theintelligent, modular computer management system of the presentinvention. Multimedia CIM 116 also interfaces CIM audio output device126, CIM audio input device 128, and CIM I/O module 130 to the computermanagement system of the present invention. However, these devices mayeither be integral to or independent from remote computer 118. Forexample, multimedia CIM 116 may interface directly to the audio in portand audio out port of remote computer 118 or may interface to anindependent audio input device, such as a microphone, and an independentaudio output device, such as a speaker.

Video port 412, keyboard port 414, and cursor control device port 416 ofremote computer 118 are connected to port 400 of multimedia CIM 116 viaa specially manufactured modular cable 418. Modular cable 418 contains afirst end with a connector for coupling modular cable 418 to multimediaCIM 116, and a second end containing three connectors for couplingmodular cable 418 to video port 412, keyboard port 414, and cursorcontrol device port 416. Preferably, separate audio ports 422 and 424are used for connecting audio output device 126 and audio input device128. In an alternate embodiment, a five or six prong modular cable canbe specially manufactured to allow port 400 of multimedia CIM 116 toconnect to the video, keyboard, cursor control device, audio in, andaudio out ports of remote computer 118, and optionally to CIM I/O module130. In yet another embodiment, multimedia CIM 116 may be connected tothe audio input and audio out ports of remote computer 118 via industrystandard audio cabling.

In the preferred embodiment of the present invention, multimedia CIM 116may be connected to the audio input and audio out ports of remotecomputer 118, CIM audio output device 126, and CIM audio input device128 via a multipurpose audio cable. The multipurpose audio cablecontains a first end that couples to CIM audio in port 424 and CIM audioout port 422. The second end of the multipurpose cable contains twoaudio input connectors and two audio output connectors. The two audioinput connectors couple to CIM audio input device 128 and the audio outport of remote computer 118. The two audio output connectors couple toCIM audio output device 126 and the audio in port of remote computer118. This cable configuration allows a system user to send audio to bothCIM audio output device 126, such as speakers, and to the audio in portof remote computer 118. Furthermore, the multipurpose cable allows asystem user to receive audio generated either internal to remotecomputer 118 or externally, such as a person speaking into a microphonethat is connected to multimedia CIM 116. Optionally, the audio cable maycontain a switching mechanism for switching between the two inputconnectors and the two output connectors located at the second end ofmodular cable.

In the preferred embodiment of the present invention, CIM I/O module 130is connected to CIM I/O port 426 via a 40-pin ribbon cable. However, asdiscussed above with respect to UST I/O module 124, it will be apparentto one of skill in the art that multimedia CIM 116 and CIM I/O module130 can be designed to utilize any type of cabling to couple CIM I/Omodule 130 to multimedia CIM 116. Also, as discussed above with respectto UST I/O module 124, CIM I/O module 130 may be designed to include oneor more ports, including varying types of ports, which interface one ormore auxiliary peripheral devices to CIM I/O module 130.

CIM CPU 406 receives keyboard and cursor control device signals fromkeyboard port 414 and cursor control device port 416 of remote computer118, respectively. Thereafter, CIM CPU 406 analyzes the received signalsand transmits information to CIM transceiver 408 via data converter 420to be used during generation of a data packet. Simultaneously, dataconverter 420 receives signals from CIM I/O module 130 and CIM audioinput device 128 via CIM I/O port 426 and CIM audio in port 424,respectively. The I/O module signals and audio signals are processed bydata converter 420 and transmitted to CIM transceiver for transmissionto MSU 112 via port 402 and cable 114.

FIG. 4B shows a schematic diagram of the preferred configuration of CIMtransceiver 408 and data converter 420. As shown, the CIM I/O modulesignals are received from CIM I/O module 130 via CIM I/O port 426 andare input to bit converter 450 located in data converter 420. Similarly,the audio signals are received from CIM audio input device 128 via USTaudio in port 424 and are converted to digital signals by analog-digitalconverter (“AD converter”) 452. The resulting digitized audio signalsare input to audio rate converter 454 which formats the rate of dataflow. Additionally, signals relating to the keyboard and cursor controldevice information are received from CIM CPU 406 and are input to serialrate converter 456 which serializes the keyboard and cursor controldevice signals.

CIM transceiver 408 combines the signals received from audio rateconverter 454, serial rate converter 456, and bit converter 450 tocreate data packets in packetizer 458 as discussed in further detailwith respect to FIG. 5. It should be noted that the I/O module signalstypically contain the same information as the auxiliary peripheraldevice signals mentioned above. The reason for this is that CIM I/Omodule 130 and UST I/O module 124 are used to interface auxiliaryperipheral devices to multimedia CIM 116 and multimedia UST 108,respectively. In addition, the data packet contains overhead data, alsodiscussed in more detail regarding FIG. 5. Thereafter, CIM transceiver408 converts the data packets to a serial format utilizing serializer460 and encodes the data packet utilizing encoder 462. Signal converter464 then conditions the data packet for transmission over cable 114 byconverting the data packet to a differential signal for transmissionover a single twisted pair located in cable 114 and by applying theproper network protocol to the data packet. The data packet is thentransmitted to port 402 for transmission to MSU 112 via cable 114.Timing circuit 466 directs serializer 460 and signal converter 464 tocreate a new data packet every twenty five (25) microseconds to ensureconstant data flow.

Keyboard, cursor control device, I/O module, and audio signals in theform of a data packet are received from MSU 112 via cable 114 at port402. Signal converter 464 located in CIM transceiver 408 converts thedata packet from a differential form to its original form and removesnetwork protocol conditioning performed by MSU 112. The data packet isnext decoded by decoder 468 and de-serialized by de-serializer 470.Timing circuit 466 instructs de-serializer 470 to de-serialize a datapacket every twenty (20) microseconds to ensure constant data packetflow. The data packet is then processed by separator 472 which parsesthe data packet into its original components.

The received audio signals are processed by audio rate converter 474.The digital audio signals are then converted to analog signals in audiodigital-to-analog converter (“DAC converter”) 476 and undergo signalamplification by signal amplifier 478. The amplified analog audiosignals are then applied to CIM audio out port 422.

The received I/O module signals are conditioned by bit shifter 480 andtransmitted to CIM I/O module 130 via CIM I/O module port 426. Thekeyboard and cursor control device signals are processed by rateconverter 482 and passed through data converter 420 to CIM CPU 406 whichuses the information contained in the signals to emulate keyboard andcursor control device signals. These emulated signals are applied tokeyboard 102 and cursor control device 106 via keyboard port 400 andcursor control device port 410, respectively (FIG. 4A).

Similarly, keyboard, cursor control device, I/O module, and audiosignals received from MSU 112 via cable 114 (FIG. 1) are received viaport 402. CIM transceiver 408 receives, de-serializes, and transmitsthese signals to data converter 420. Data converter 420 processes theaudio signals and transmits the audio signals to CIM audio output device126 via CIM audio out port 422. The received I/O module signals areprocessed by data converter 420 and then transmitted to CIM I/O module130 via CIM I/O port 426. The keyboard and cursor control device signalsare processed by data converter 420 and then are passed to CIM CPU 406,which uses the information contained in the signals to emulate keyboardand cursor control device signals. These emulated signals are applied tokeyboard port 414 and cursor control device port 416 via port 400.

As discussed in greater detail above for FIG. 2A with respect to UST CPU308, CIM CPU 406 is also programmed to emulate keyboard and cursorcontrol device signals that are compatible with the communicationprotocol of the connected remote computer 118, even though the originalkeyboard and cursor control device signals generated at the originationmultimedia UST 108 may not be compatible with the remote computer'sprotocol.

Video signals are transmitted from video port 412 of remote computer 118to multimedia CIM 116 via modular cable 418 to port 400. From port 400,the video signals are transmitted to video driver 404, which convertsthe standard red, green, and blue components of the video signal todifferential signals for transmission through port 402 to cable 114.Each color signal is transmitted via its own twisted pair cablecontained within cable 114 (when transmitted from multimedia CIM 116 toMSU 112) and single cable 110 (when transmitted from MSU 112 tomultimedia UST 108) (FIG. 1). Furthermore, video driver 404 appends thehorizontal and vertical synchronization signals to one of the red,green, or blue video signals to allow all five components of the videosignal to be transmitted via only three twisted pair cables of cables110 or 114. That is, the horizontal and vertical synchronization signalsare each transmitted on their own color signal—not the same colorsignal.

Furthermore, multimedia CIM 116 contains memory unit 410, which storesthe address and status of the connected remote computer 118. Thus, if aspecific remote computer 118 is not functioning properly, it is easy toassess which remote computer 118 has malfunctioned. In addition, thedevice address facilitates proper switching of the keyboard, cursorcontrol device, audio, and auxiliary peripheral device signals since thedevice address is included in the generated data packets that containthe transmitted signal information. Therefore, the information containedin memory unit 410 maintains the modular nature of the computermanagement system of the present invention.

Finally, in the preferred embodiment of the present invention, remotecomputer 118 provides power to multimedia CIM 116. Thus, the preferredembodiment of the present invention eliminates the equipment, cabling,and space required for a dedicated multimedia CIM 116 power source.

Referring now to FIG. 6, shown is a timing diagram depicting thetransmission of data packet 500 from multimedia UST 108 to multimediaCIM 116 and vice versa according to the preferred embodiment of theinvention. Multimedia CIM 116 initially forms a data packet from thekeyboard, cursor control device, administrative, audio, and auxiliaryperipheral device signals. Multimedia UST 108 conditions the data packetfor transmission to MSU 112 via cable 110 (FIG. 1) in UST transmissionstep 602. Typically, the formation of the data packet takesapproximately 6.4 microseconds. While undergoing transmission, the datapacket experiences approximately a 1.5 nanosecond per foot cable delay.

The data packet is received at MSU 112 step 604. As previouslydescribed, MSU 112 processes the data packet to determine the propermultimedia CIM 116 to which to transmit the data packet. This processingtypically takes about 0.2 microseconds. MSU 112 then retransmits thedata packet to multimedia CIM 116 via cable 114 step 606. Again, thedata packet experiences about a 1.5 nanosecond per foot cable delaywhile being transmitted over cable 114.

Multimedia CIM 116 receives and processes the data packet in step 608.The keyboard, cursor control device, audio, and auxiliary peripheraldevice signals are then transmitted to the appropriate attachedperipheral devices (FIG. 4A and FIG. 4B). In response to the inbounddata packet, multimedia CIM 116 prepares a new data packet containingkeyboard, cursor control device, administrative, audio, and auxiliaryperipheral device signals formed at remote computer 118. The formationof the new outbound data packet by multimedia CIM 116 takesapproximately 6.4 microseconds. After the formation of the new outbounddata packet is complete, multimedia CIM 116 transmits the data packet toMSU 112 via cable 114 in step 610. The data packet experiences about a1.5 nanosecond per foot cable delay during transmission over cable 114.

MSU 112 receives the data packet from multimedia CIM 116 step 612. MSU112 processes the data packet to determine the proper multimedia UST 108to which to transmit the data packet. This processing typically takesabout 0.2 microseconds. MSU 112 then retransmits the data packet tomultimedia UST 108 via single cable 110 in step 614. The data packetexperiences approximately a 1.5 nanosecond per foot cable delay whilebeing transmitted over cable 110 to multimedia UST 108.

The data packet is received at multimedia UST 108 in step 616. Once thedata packet has been received, multimedia UST 108 transmits a new datapacket to multimedia CIM 116 according to the timing diagram justdescribed. Transmission of a data packet from multimedia UST 108 tomultimedia CIM 116 and from multimedia CIM 116 to multimedia UST 108takes approximately twenty (20) microseconds for completion.Importantly, the timing diagram of FIG. 6 is merely exemplary of thetiming of the data packets within the system according to the invention.Other transmission times are possible while maintaining the purpose andfunction of the invention.

Referring next to FIG. 7, disclosed is an alternate embodiment of theintelligent, modular computer management system of the present inventionin which the system is expanded to include two MSUs 801 and 802, eachhaving eight (8) inputs and thirty-two (32) outputs. This configurationallows sixteen (16) USTs 108 to access and operate thirty-two (32)connected computers 118. In this alternate embodiment, each UST 108 maybe linked to either first MSU 801 or second MSU 802 via cable 110. Allsignals received at UST 108 are transmitted via its connected MSU (i.e.,either first MSU 801 or second MSU 802) to CIM 116 that is connected tothe desired connected computer 118. In this alternate embodiment, CIM116 provides connectors for two (2) cables 114 to allow it to connect toboth first MSU 801 and second MSU 802. Thus, CIM 116 allows sixteen (16)user workstations 100 to operate thirty-two (32) connected computers118.

In addition, this embodiment allows two (2) user workstations 100 tosimultaneously access and operate the same connected computer 118.Alternatively, this embodiment allows a first user workstation 100 toinform a second user workstation 100 that a connected computer 118 is inuse and, therefore, access to it is restricted.

Turning next to FIG. 8, disclosed is another alternate embodiment of theremote computer management system of the present invention. The use offorty (40) total MSUs (i.e., eight (8) first tier MSUs 902 andthirty-two (32) second tier MSUs 904), wherein each first tier MSU 902and second tier MSU 904 has eight (8) inputs and thirty-two (32)outputs, allows sixty-four (64) user workstations 100 to operate andaccess one thousand twenty four (1,024) connected computers 118. In thisalternate embodiment, each UST 108 is directly linked to one of eight(8) first tier MSUs 702 via single CAT 5 cable 906. First tier MSU 902transmits all signals received from user workstation 100 via single CAT5 cable 908 to second tier MSU 904 that is connected to the CIM 116associated with the desired connected computer 118. Second tier MSU 904then transmits the received signals to the respective CIM 116 via singleCAT 5 cable 910, whereupon CIM 116 applies these signals to therespective ports of connected computer 118. In this embodiment, thesecond tier of MSUs 904 comprises thirty-two (32) units. Each secondtier MSU 904 is coupled to multiple CIMs 116, which provide a directconnection to each of the one thousand twenty four (1,024) potentialconnected computers 118 via single CAT 5 cables 910.

Although FIG. 8 depicts the configuration used to access and control onethousand twenty four (1,024) connected computers 118 from sixty-four(64) user workstations 100, many other system configurations areavailable to allow a greater number of user workstations 100 to beconnected to a greater number of connected computers 118. For example,the number of MSU tiers may be increased, or, alternatively, hubs may beincorporated. Also, each MSU may be designed to comprise more than eight(8) inputs and more than thirty-two (32) outputs to further increase thesystem capacity.

While the present invention has been described with reference to thepreferred embodiment and several alternative embodiments, whichembodiments have been set forth in considerable detail for the purposesof making a complete disclosure of the invention, such embodiments aremerely exemplary and are not intended to be limiting or represent anexhaustive enumeration of all aspects of the invention. The scope of theinvention, therefore, shall be defined solely by the following claims.Further, it will be apparent to those of skill in the art that numerouschanges may be made in such details without departing from the spiritand the principles of the invention. It should be appreciated that thepresent invention is capable of being embodied in other forms withoutdeparting from its essential characteristics.

1. A computer management system comprising: a workstation including atleast one of the group consisting of a keyboard, a video monitor, acursor control device, an audio device, and an auxiliary peripheraldevice. a plurality of computers; a switching system with circuitry fortransmitting keyboard, cursor control device, audio, and auxiliaryperipheral device signals from said workstation to one of said remotecomputers, said switching system further comprising circuitry fortransmitting keyboard, video, cursor control device, and auxiliaryperipheral device signals from said one of said remote computers to saidworkstation; at least one eight conductor cable for coupling at leastone of said computer interface and said user interface to saidmanagement unit; wherein said user interface receives at least one ofuser keyboard signals, user mouse signals, and user audio signals fromsaid user keyboard, said user mouse, and said user audio device,respectively; and wherein said user interface transmits said userkeyboard signals, said user mouse signals, and said user audio signalsvia said eight conductor cable to said computer via said managementunit.
 2. A computer management system according to claim 1, wherein saidcomputer interface is further coupled to at least one computer audiodevice.
 3. A computer management system according to claim 2, whereinsaid computer interface receives computer keyboard signals from saidcomputer, computer mouse signals from said computer, computer videosignals from said computer, and computer audio signals from at least oneof said computer and said computer audio devices; and wherein saidcomputer interface transmits said computer keyboard signals, saidcomputer video signals, said computer mouse signals, and said computeraudio signals via said eight conductor cable to said user interface viasaid management unit.
 4. A computer management system according to claim1, wherein said eight conductor cable comprises at least one RegisteredJack 45 (“RJ-45”) connector.
 5. A computer management system accordingto claim 3, wherein said eight conductor cable comprises a first,second, and third twisted pair of wires that transmit red, green, andblue components of said computer video signals, respectively, andfurther comprises a fourth twisted pair of wire that transmits at leastone of said computer keyboard signals, said computer mouse signals, andsaid computer audio signals.
 6. A computer management system accordingto claim 5, wherein a computer horizontal synchronization signal isencoded onto one of said green component, said red component, and saidblue component of said computer video signals.
 7. A computer managementsystem according to claim 5, wherein a computer vertical synchronizationsignal is encoded onto one of said green component, said red component,and said blue component of said computer video signals.
 8. A computermanagement system according to claim 2, wherein at least one of saiduser audio device and said computer audio device are selected from thegroup consisting of a microphone, an analog playback device, a digitalplayback device, a cassette player, a compact disc player, a DigitalVideoDisc player, a television, a computer, a telephone, a cellulartelephone, a projector, a camera, and a personal digital assistant.
 9. Acomputer management system according to claim 2, wherein said computeraudio device is at least one of an audio in port of said computer and anaudio out port of said computer.
 10. A computer management systemaccording to claim 2, wherein at least one of said user audio device andsaid computer audio device are selected from the group consisting of aspeaker, an audio headset, a projector, an analog audio recordingdevice, a digital audio recording device, a second computer, a cassetterecorder, a Compact Disc writer, a Digital VideoDisc writer, atelevision, a camera, a telephone, a cellular telephone, and a personaldigital assistant.
 11. A computer management system according to claim1, further comprising: an audio cable for coupling said user audiodevice to said user interface and for coupling said computer audiodevice to said computer interface.
 12. A computer management systemaccording to claim 11, wherein said audio cable bidirectionallytransmits audio signals.
 13. A computer management system according toclaim 2, further comprising: an audio cable for coupling said computerinterface to at least one of an audio in port of said computer, an audioout port of said computer, and said computer audio device, wherein saidaudio cable bidirectionally transmits audio signals.
 14. A computermanagement system according to claim 12, wherein said computer interfacecable comprises at least one of a first connector for coupling saidcomputer interface cable to said computer interface, a second connectorfor coupling said computer interface cable to a keyboard port of saidcomputer, a third connector for coupling said computer interface cableto a video port of said computer, a fourth connector for coupling saidcomputer interface cable to a mouse port of said computer, a fifthconnector and a sixth connector for coupling said computer interfacecable to a first and a second of said computer audio devices, and aseventh and an eighth connector for coupling said computer interfacecable to an audio in port of said computer and an audio out port of saidcomputer; wherein said first computer audio device comprises an audioinput device; and wherein said second computer audio device comprises anaudio output device.
 15. A computer management system according to claim14, wherein said computer interface cable transmits at least one of saiduser keyboard signals, said user mouse signals, and said user audiosignals from said computer interface to at least one of said computerand said computer audio devices; and wherein said computer interfacecable transmits at least one of said computer keyboard signals, saidcomputer video signals, said computer mouse signals, and said computeraudio signals to said computer interface from at least one of saidcomputer and said computer audio devices.
 16. A computer managementsystem comprising: at least one computer; at least one computerinterface coupled to said computer via a computer interface cable; atleast one management unit coupled to said computer interface; and atleast one user interface coupled to said management unit and coupled toat least one of a user keyboard, a user video monitor, a user mouse, auser audio device, and a user auxiliary peripheral device; wherein saiduser interface receives at least one of user keyboard signals, usermouse signals, user audio signals, and user auxiliary peripheral devicesignals; and wherein said user interface transmits said user keyboardsignals, said user mouse signals, and said user auxiliary peripheraldevice signals to said computer via said management unit.
 17. A computermanagement system according to claim 16, wherein said computer interfaceis further coupled to at least one of a computer audio device and acomputer auxiliary peripheral device.
 18. A computer management systemaccording to claim 17, wherein said computer interface receives computerkeyboard signals from said computer, computer mouse signals from saidcomputer, computer video signals from said computer, computer audiosignals from at least one of said computer and said computer audiodevices, and computer auxiliary device signals from said computerauxiliary peripheral device; and wherein said computer interfacetransmits said computer keyboard signals, said computer video signals,said computer mouse signals, said computer audio signals, and saidcomputer auxiliary peripheral signals to said user interface via saidmanagement unit.
 19. A computer management system according to claim 16,wherein said user interface transmits said user keyboard signals, saiduser mouse signals, said user audio signals, and said user audioperipheral device signals to said computer via said management unit. 20.A computer management system according to claim 18, further including:at least one eight conductor cable for coupling at least one of saidcomputer interface and said user interface to said management unit. 21.A computer management system according to claim 20, wherein said eightconductor cable comprises at least one Registered Jack 45 (“RJ-45”)connector.
 22. A computer management system according to claim 20,wherein said eight conductor cable comprises a first, second, and thirdtwisted pair of wires that transmit red, green, and blue components ofsaid computer video signals, respectively, and further comprises afourth twisted pair of wire that transmits at least one of said computerkeyboard signals, said computer video signals, said computer mousesignals, said computer audio signals, and said computer auxiliaryperipheral device signals.
 23. A computer management system according toclaim 22, wherein a computer horizontal synchronization signal isencoded onto one of said green component, said red component, and saidblue component of said computer video signals.
 24. A computer managementsystem according to claim 22, wherein a computer verticalsynchronization signal is encoded onto one of said green component, saidred component, and said blue component of said computer video signals.25. A computer management system according to claim 17, furthercomprising: at least one of a user auxiliary peripheral module and acomputer auxiliary peripheral module; wherein said user auxiliaryperipheral module couples said user auxiliary peripheral device to saiduser interface; and wherein said computer auxiliary peripheral modulecouples said computer auxiliary peripheral device to said computerinterface.
 26. A computer management system according to claim 25,wherein said user auxiliary peripheral module and said computerauxiliary peripheral module are coupled to said user interface and saidcomputer interface, respectively, via a forty pin ribbon cable.
 27. Acomputer management system according to claim 17, wherein at least oneof said user auxiliary peripheral device and said computer auxiliaryperipheral device are selected from the group consisting of a serialport device, a Universal Serial Bus device, a Recommended Standard 232device, a PS/19 device, a parallel device, a firewire device, aRegistered Jack 28 device, a Registered Jack 21 device, a RegisteredJack 45 device, a Registered Jack 48 device, a British Naval Connectordevice, a Centronics device, an Advanced Technology device, aSuper-Video device, a Digital Video Interface device, an IntegratedDevelopment Environment device, a Fiber Distributed Data Interfacedevice, a switch closure device, or a Small Computer System Interfacedevice.
 28. A computer management system according to claim 17, whereinat least one of said user auxiliary peripheral device and said computerauxiliary peripheral device are selected from the group consisting of akeyboard, a mouse, an optical mouse, a trackball, a Universal Serial Buskeyboard adapter, a Universal Serial Bus mouse adapter a secondcomputer, a port expander, a Bluetooth device, a cellular telephone, aweb camera, a floppy disk drive, a hard disk drive, a Universal SerialBus Flash Drive, a digital media reader, a digital media writer, amicrophone, a speaker, a subwoofer, a scanner, a copier, a printer, aprojector, a television, an analog monitor, a digital monitor, a videocapture device, a modem, a hub, a router, a switch, a cable modem, aDigital Subscriber Line modem, a wireless network hub, a wirelessnetwork router, a wireless access point, a print server, a wirelessprint server, an Ethernet adapter, an analog audio playback device, ananalog audio recording device, a digital audio playback device, adigital audio recording device, a tape drive, a storage backup device, ajoystick, a game pad, a power supply, an uninterruptible power supply, aUniversal Serial Bus hub, a Compact Disc Read Only Memory device, aCompact Disc write device, a Compact Disc re-write device, an audiodevice, a Digital VideoDisc Random Access Memory device, a camera, acassette recorder, a headset, a camcorder, a fingerprint reader, aretina scanner, a biometric authentication device, and a personaldigital assistant.
 29. A computer management system according to claim17, wherein at least one of said user audio device and said computeraudio device is a microphone, an analog playback device, a digitalplayback device, a cassette player, a compact disc player, a DigitalVideoDisc player, a television, a computer, a telephone, a cellulartelephone, a projector, a camera, and a personal digital assistant. 30.A computer management system according to claim 17, wherein saidcomputer audio device is at least one of an audio in port of saidcomputer and an audio out port of said computer.
 31. A computermanagement system according to claim 17, wherein at least one of saiduser audio device and said computer audio device is a speaker, an audioheadset, a projector, an analog audio recording device, a digital audiorecording device, a second computer, a cassette recorder, a Compact Discwriter, a Digital VideoDisc writer, a television, a camera, a telephone,a cellular telephone, and a personal digital assistant.
 32. A computermanagement system according to claim 16, further comprising: at leastone audio cable; wherein said audio cable couples at least one of saiduser audio device to said user interface and said computer audio deviceto said computer interface.
 33. A computer management system accordingto claim 32, wherein said audio cable bidirectionally transmits audiosignals.
 34. A computer management system according to claim 17, furthercomprising: an audio cable for coupling said computer interface to atleast one of an audio in port of said computer, an audio out port ofsaid computer, and at least one of said computer audio devices; whereinsaid audio cable bidirectionally transmits audio signals.
 35. A computermanagement system according to claim 25, wherein said computer interfacecable comprises at least one of a first connector for coupling saidcomputer interface cable to said computer interface, a second connectorfor coupling said computer interface cable to a keyboard port of saidcomputer, a third connector for coupling said computer interface cableto a video port of said computer, a fourth connector for coupling saidcomputer interface cable to a mouse port of said computer, a fifthconnector and a sixth connector for coupling said computer interfacecable to a first and a second of said computer audio devices, a seventhand an eighth connector for coupling said computer interface cable to anaudio in port of said computer and an audio out port of said computer,and a ninth connector for coupling said computer interface cable to atleast one of said auxiliary peripheral device and said auxiliaryperipheral device module; wherein said first computer audio devicecomprises an audio input device; and wherein said second computer audiodevice comprises an audio output device.
 36. A computer managementsystem according to claim 35, wherein said computer interface cabletransmits at least one of said user keyboard signals, said user mousesignals, said user audio signals, and said user auxiliary peripheraldevice signals from said computer interface to at least one of saidcomputer and said computer audio devices; and wherein said computerinterface cable transmits at least one of said computer keyboardsignals, said computer video signals, said computer mouse signals, saidcomputer audio signals, and said computer auxiliary peripheral devicesignals to said computer interface from at least one of said computerand said computer audio devices.
 37. A method of transmitting signalsvia a computer management system comprising the steps of: receivingkeyboard signals, video signals, mouse signals, and audio signals at atransmission node; forming a data packet comprising said keyboardsignals, said mouse signals, and said audio signals; encoding a verticalsynchronization signal onto one of a red, blue, and green component ofsaid video signals; encoding a horizontal synchronization signal ontoone of said red component, said blue component, and said green componentof said video signals; transmitting said data packet to a receiving nodevia a first pair of wires in an eight conductor cable; transmitting saidred component of said video signals to said receiving node via a secondpair of wires in said eight conductor cable; transmitting said bluecomponent of said video signal to said receiving node via a fourth pairof wires in said eight conductor cable; and transmitting said greencomponent of said video signal to said receiving node via a third pairof wires in said eight conductor cable.
 38. A method according to claim37, further comprising the steps of: converting said data packet to adifferential signal; converting said red component of said video signalsto a differential signal; converting said green component of said videosignals to a differential signal; and converting said blue component ofsaid video signals to a differential signal.
 39. A method according toclaim 37, wherein said data packet comprises a first section forrepresenting a length of said data packet, a second section forrepresenting said audio signals, and a third section for representingsaid keyboard signals and said mouse signals.
 40. A method according toclaim 37, wherein said audio device is selected from the groupconsisting of a microphone, an analog playback device, a digitalplayback device, a cassette player, a compact disc player, a DigitalVideoDisc player, a television, a computer, a telephone, a cellulartelephone, a projector, a camera, and a personal digital assistant. 41.A method according to claim 37, wherein said audio device is at leastone of an audio in port of said computer and an audio out port of saidcomputer.
 42. A method according to claim 37, wherein said audio deviceis selected from the group consisting of a speaker, an audio headset, aprojector, an analog audio recording device, a digital audio recordingdevice, a second computer, a cassette recorder, a Compact Disc writer, aDigital VideoDisc writer, a television, a camera, a telephone, acellular telephone, and a personal digital assistant.
 43. A method oftransmitting signals via a computer management system comprising thesteps of: receiving keyboard signals, video signals, mouse signals, andauxiliary peripheral device signals at a transmission node; forming adata packet comprising said keyboard signals, said mouse signals, andsaid auxiliary peripheral signals; encoding a vertical synchronizationsignal onto one of a red, blue, and green component of said videosignals; encoding a horizontal synchronization signal onto one of saidred component, said blue component, and said green component of saidvideo signals; transmitting said data packet to a receiving node via afirst pair of wires in an eight conductor cable; transmitting said redcomponent of said video signals to said receiving node via a second pairof wires in said eight conductor cable; transmitting said blue componentof said video signal to said receiving node via a fourth pair of wiresin said eight conductor cable; and transmitting said green component ofsaid video signal to said receiving node via a third pair of wires insaid eight conductor cable.
 44. A method according to claim 43, furthercomprising the steps of: converting said data packet to a differentialsignal; converting said red component of said video signals to adifferential signal; converting said green component of said videosignals to a differential signal; and converting said blue component ofsaid video signals to a differential signal.
 45. A method according toclaim 44, wherein said data packet comprises a first section forrepresenting a length of said data packet, a second section forrepresenting said auxiliary peripheral device signals, and a thirdsection for representing said keyboard signals and said mouse signals.46. A method according to claim 43, wherein said auxiliary peripheraldevice is selected from the group consisting of a serial port device, aUniversal Serial Bus device, a Recommended Standard 232 device, a PS/19device, a parallel device, a firewire device, a Registered Jack 28device, a Registered Jack 21 device, a Registered Jack 45 device, aRegistered Jack 48 device, a British Naval Connector device, aCentronics device, an Advanced Technology device, a Super-Video device,a Digital Video Interface device, an Integrated Development Environmentdevice, a Fiber Distributed Data Interface device, a switch closuredevice, or a Small Computer System Interface device.
 47. A methodaccording to claim 43, wherein said auxiliary peripheral device isselected from the group consisting of a keyboard, a mouse, an opticalmouse, a trackball, a Universal Serial Bus keyboard adapter, a UniversalSerial Bus mouse adapter a second computer, a port expander, a Bluetoothdevice, a cellular telephone, a web camera, a floppy disk drive, a harddisk drive, a Universal Serial Bus Flash Drive, a digital media reader,a digital media writer, a microphone, a speaker, a subwoofer, a scanner,a copier, a printer, a projector, a television, an analog monitor, adigital monitor, a video capture device, a modem, a hub, a router, aswitch, a cable modem, a Digital Subscriber Line modem, a wirelessnetwork hub, a wireless network router, a wireless access point, a printserver, a wireless print server, an Ethernet adapter, an analog audioplayback device, an analog audio recording device, a digital audioplayback device, a digital audio recording device, a tape drive, astorage backup device, a joystick, a game pad, a power supply, anuninterruptible power supply, a Universal Serial Bus hub, a Compact DiscRead Only Memory device, a Compact Disc write device, a Compact Discre-write device, an audio device, a Digital VideoDisc Random AccessMemory device, a camera, a cassette recorder, a headset, a camcorder, afingerprint reader, a retina scanner, a biometric authentication device,and a personal digital assistant.